SU899583A1 - Process for producing modified polyethyleneterephthalate - Google Patents

Description

This invention relates to a process for the production of modified polyethylene terephthalate (PET), which is used to produce lavsan-type fiber, which has good dispersion of dyestuffs. Synthetic polyester fiber based on PET has a high crystallinity and dense packing of polymer chains, as a result of which the diffusion of the dye proceeds very slowly during the dyeing process, which makes it necessary to apply special methods more brilliant - suppression at elevated temperature (about) or in the presence of carriers. A method is known for improving the paint sprayability of polyethylene terephthalate fiber by chemical modification of PET in the process of its production by introducing monomer units and blocks into the polyester chain, resulting in a violation of the crystallinity and regularity of the structure of macromolecules 1. However, it is usually understood that the characteristics of the fiber and its thermal stability are understood. A known method for producing PET. modified day and triepoxy compounds. At the same time, fibers acquire an affinity for dyes; physicomechanical properties are similar to those of fibers based on unmodified PET; the duration of the polycondection stage is 4h 2}. The closest to the invention in its technical essence and the effect achieved is a method for producing modified PET by reacting terephthalic acid and ethylene glycol in the presence of an epoxy-containing modifier with a subsequent polycovalence of the obtained product. As a modifier, diepoxy compounds of the general formula RjCH-Ri-CHj-X-CHj-CRs-CHR are used; where RI-R4 - H, alkyl, oxide Kiel; X is a divalent group of the type alkylene, arylene, cycloalkylene, in the amount of 0.001-1 mol.%. Fibers of PET based on these compounds, oOjrajiamT by upstream distillation of almost 85% nOperwiecKoro amount of water are injected with 0.2 ml of a 15% solution, heated to 225-230 seconds and the excess is distilled off within 1-1.5 hours ethylene glycol. About, And g (0.5 mol.%) Of di- (2,3-epoxycyclohexyl) oxide are added, incubated for 1 hour at 225230 ° C in a stream of argon, then the system is evacuated to a pressure of 1 mm and reacted at a bath temperature of 270 ° C within 70 min. A colorless polymer is obtained having a m.p. 242 248С (on the smelting table); “D 0.28 (0.5% solution in m-cresol); dyed 62% (degree of sorption dye l from the bath). Example 4. The synthesis was carried out according to the procedure of Example 3, using 0.32 g (1.5 mol.%) Of di (2, 3-xpoxycyclohexane 1) oxide as a modifier and a polycondensation time of 1 hour. Modified PET is obtained having pl. 235-243C; i 0,27; the degree of sorption of dye fibers based on it is 71%. Example 5. Synthesis of modified PET was carried out as described in Example 3, when used as. modifier 0.5 g (1.5 mol.%) D) - (2,3-e 11-oxycyclic-exyl) adsnat and polycondensation time 70 min. Get modified PET, imyushy t, pl. 249-253 ° C; Tsu. 0.27; the degree of sorption of dye fibers based on it is 77%. Example 6. Synthesis of modified PET was carried out as described in Example 3, using 0.25 g (0.75 mol%) di- (2,3-zpoxycyclohexyl) adipate as a modifier and polycondensation time 45 minutes. Get midified PET having t. Pl. 244-249 ° C; 1 ud0,30; the degree of sorption of the dye fiber 79%, Example 7. The synthesis is carried out on. the procedure of example 3, when using as a modifier 0.17 g (0.5 mol%) of di (2,3-epoxy-xyl) xyloxy acid and polycondensation time 70 min. The resulting PET has t, pl. 249-253 C; Y beats 0.27; the degree of sorption of the dye fiber 75%. Comparative physicomechanical properties of PET and fiber (based on it are given in the table.

Specific viscosity 0.5%

solution at 20 ° C

Density, g / cm

Breaking strength

g / denier

Z

Modulus of elasticity, kg.m.m

Explosive elongation,%

The degree of sorption of dispersed

dye (from the bath),%

Temperature 5% loss

in weight, C

The duration of the polycondensation, h

As can be seen from the table, fibers based on PET modified with cycloaliphatic diepoxides compared with unmodified, 24 1.37

3.95

4.53

1200

27.5

48.7 67.3

63

356

bath fibers have improved dyeability and increased modulus value. 789958 The fibers obtained by the proposed method have an increased value of breaking at break. The use of cyclic aliphatic monoepoxy derivatives makes it possible to shorten the condensation stage. The invention allows the improvement of the physicomechanical properties of poly (ethylene terephthalate) fiber while retaining the sorptive capacity of the dye and accelerating the stage to solids condensation.

Claims (3)

Invention Formula A method of producing modified terephthalate polyethylene terephthalate by reacting terephthalic acid and styrene in the presence of a xpox-containing modifier followed by polycondensation of the product obtained, characterized in that, in order to improve the physicomechanical properties of polytelephthalate fiber with an X-Q-; -OC (CHi) 4CO-, and the modifier is introduced prior to the polycondensation step. Sources of information taken into account in the examination 1. Cocks B. Century Polyester fibers. M., Himi, 1976, p. 228-230. 2. Japan patent number 10627, for l. 26 d 6, published. 1967. 3. Japan patent number 10625, cl. 26 d 6, published. 1967 (prototype). They do not increase the ability to dye sorption and accelerate the polycondensation stage of the research institute, using 0.5-1.5 mol% per epoxy containing modifier, per mole of terephthalic acid of the ccloataphate diepoxc of the general formula